diff --git a/src/interfaces/wallet.h b/src/interfaces/wallet.h
index 3339fcafbc..06ff08caf8 100644
--- a/src/interfaces/wallet.h
+++ b/src/interfaces/wallet.h
@@ -14,13 +14,14 @@
 #include <util/message.h>
 #include <util/ui_change_type.h>
 
+#include <cstdint>
 #include <functional>
 #include <map>
 #include <memory>
 #include <psbt.h>
-#include <stdint.h>
 #include <string>
 #include <tuple>
+#include <type_traits>
 #include <utility>
 #include <vector>
 
@@ -37,7 +38,7 @@ struct CRecipient;
 struct PartiallySignedTransaction;
 struct WalletContext;
 struct bilingual_str;
-typedef uint8_t isminefilter;
+using isminefilter = std::underlying_type<isminetype>::type;
 
 namespace interfaces {
 
diff --git a/src/rpc/mining.cpp b/src/rpc/mining.cpp
index 026ceb2fc2..50956048da 100644
--- a/src/rpc/mining.cpp
+++ b/src/rpc/mining.cpp
@@ -1169,10 +1169,10 @@ static RPCHelpMan estimatesmartfee()
     UniValue errors(UniValue::VARR);
     FeeCalculation feeCalc;
     CFeeRate feeRate{fee_estimator.estimateSmartFee(conf_target, &feeCalc, conservative)};
-    CFeeRate min_mempool_feerate{mempool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000)};
-    CFeeRate min_relay_feerate{::minRelayTxFee};
-    feeRate = std::max({feeRate, min_mempool_feerate, min_relay_feerate});
     if (feeRate != CFeeRate(0)) {
+        CFeeRate min_mempool_feerate{mempool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000)};
+        CFeeRate min_relay_feerate{::minRelayTxFee};
+        feeRate = std::max({feeRate, min_mempool_feerate, min_relay_feerate});
         result.pushKV("feerate", ValueFromAmount(feeRate.GetFeePerK()));
     } else {
         errors.push_back("Insufficient data or no feerate found");
diff --git a/src/wallet/ismine.h b/src/wallet/ismine.h
index 38ed7e7770..8605547cf2 100644
--- a/src/wallet/ismine.h
+++ b/src/wallet/ismine.h
@@ -8,8 +8,9 @@
 
 #include <script/standard.h>
 
-#include <stdint.h>
 #include <bitset>
+#include <cstdint>
+#include <type_traits>
 
 class CWallet;
 class CScript;
@@ -35,8 +36,7 @@ class CScript;
  * ISMINE_USED: the scriptPubKey corresponds to a used address owned by the wallet user.
  *
  */
-enum isminetype : unsigned int
-{
+enum isminetype : unsigned int {
     ISMINE_NO         = 0,
     ISMINE_WATCH_ONLY = 1 << 0,
     ISMINE_SPENDABLE  = 1 << 1,
@@ -46,7 +46,7 @@ enum isminetype : unsigned int
     ISMINE_ENUM_ELEMENTS,
 };
 /** used for bitflags of isminetype */
-typedef uint8_t isminefilter;
+using isminefilter = std::underlying_type<isminetype>::type;
 
 /**
  * Cachable amount subdivided into watchonly and spendable parts.
diff --git a/test/functional/test_framework/messages.py b/test/functional/test_framework/messages.py
index a39d44b67a..694d4f580d 100755
--- a/test/functional/test_framework/messages.py
+++ b/test/functional/test_framework/messages.py
@@ -62,9 +62,9 @@ MSG_TYPE_MASK = 0xffffffff >> 2
 
 FILTER_TYPE_BASIC = 0
 
-# Serialization/deserialization tools
 def sha256(s):
-    return hashlib.new('sha256', s).digest()
+    return hashlib.sha256(s).digest()
+
 
 
 def hash256(s):
diff --git a/test/sanitizer_suppressions/ubsan b/test/sanitizer_suppressions/ubsan
index e1a49e9544..46a5769b18 100644
--- a/test/sanitizer_suppressions/ubsan
+++ b/test/sanitizer_suppressions/ubsan
@@ -82,12 +82,8 @@ implicit-signed-integer-truncation:addrman.h
 implicit-signed-integer-truncation:chain.h
 implicit-signed-integer-truncation:crypto/
 implicit-signed-integer-truncation:leveldb/
-implicit-signed-integer-truncation:miner.cpp
-implicit-signed-integer-truncation:net.cpp
-implicit-signed-integer-truncation:streams.h
 implicit-signed-integer-truncation:test/arith_uint256_tests.cpp
 implicit-signed-integer-truncation:test/skiplist_tests.cpp
-implicit-signed-integer-truncation:torcontrol.cpp
 implicit-unsigned-integer-truncation:*/include/c++/
 implicit-unsigned-integer-truncation:crypto/
 implicit-unsigned-integer-truncation:leveldb/